Question

我正在使用codeigniter，我需要在查询中使用聚合函数。所以我有这个问题。

"SELECT Dated, CASE WHEN `Account_ID` = 2 then SUM(Total_Bricks) ELSE 0 end as 'Nadeem', 
CASE WHEN Account_ID = 2 then SUM(Kaat_Bricks) ELSE 0 end as 'NadeemKaat', 
CASE WHEN `Account_ID` = 7 then SUM(Total_Bricks) ELSE 0 end as 'Abid', 
CASE WHEN Account_ID = 7 then SUM(Kaat_Bricks) ELSE 0 end as 'AbidKaat', 
CASE WHEN `Account_ID` = 8 then SUM(Total_Bricks) ELSE 0 end as 'Sajid', 
CASE WHEN Account_ID = 8 then SUM(Kaat_Bricks) ELSE 0 end as 'SajidKaat' 
FROM `tblstockdetail` GROUP BY `Dated`"

我通过一个简单的foreach循环生成了这个查询

$stock = $this->Kharkaar_Model->get_stockdetail();

        $sql = '"SELECT Dated, ';

        $numItems = count($stock);
        $i = 0;
        foreach ($stock as $key => $value) 
        {

            if(++$i === $numItems)
            {
                $sql.= "CASE WHEN `Account_ID` = ".$value['Account_ID']." then SUM(Total_Bricks) ELSE 0 end as '".$value['AccountName']."', <br /> 
            CASE WHEN Account_ID = ".$value['Account_ID']." then SUM(Kaat_Bricks) ELSE 0 end as '".$value['AccountName']."Kaat' <br /> FROM `tblstockdetail` GROUP BY `Dated`";
            }
            else
            {
                $sql.= "CASE WHEN `Account_ID` = ".$value['Account_ID']." then SUM(Total_Bricks) ELSE 0 end as '".$value['AccountName']."', <br /> 
            CASE WHEN Account_ID = ".$value['Account_ID']." then SUM(Kaat_Bricks) ELSE 0 end as '".$value['AccountName']."Kaat', <br /> ";

            }

        }

        $sql.= '"';

现在当我试图获得此查询的结果时

$result = $this->db->query($sql);

它给我一个语法错误，否则当我把这个查询直接放入

$result = $this->db->query(// string query here );

运行正常。

Answer 1

您的foreach应该是这样的

$stock = $this->Kharkaar_Model->get_stockdetail();

$sql = "SELECT Dated, ";

$numItems = count($stock);
$i = 0;
foreach ($stock as $key => $value) 
{

    if(++$i === $numItems)
    {
        $Account_ID = $value['Account_ID'];
        $AccountName = $value['AccountName'];

        $sql.= "CASE WHEN `Account_ID` =  $Account_ID then SUM(Total_Bricks) ELSE 0 end as $AccountName, 
        CASE WHEN Account_ID = $Account_ID then SUM(Kaat_Bricks) ELSE 0 end as $AccountName 
        FROM `tblstockdetail` GROUP BY `Dated`";
    }
    else
    {
        $sql.= "CASE WHEN `Account_ID` = $Account_ID then SUM(Total_Bricks) ELSE 0 end as $AccountName,
        CASE WHEN Account_ID = $Account_ID then SUM(Kaat_Bricks) ELSE 0 end as $AccountName";

    }

}

如果TRUE

"SELECT Dated, 
CASE WHEN `Account_ID` =  $Account_ID then SUM(Total_Bricks) ELSE 0 end as $AccountName, 
CASE WHEN Account_ID = $Account_ID then SUM(Kaat_Bricks) ELSE 0 end as $AccountName 
FROM `tblstockdetail` GROUP BY `Dated`"

如果FALSE

"SELECT Dated, 
CASE WHEN `Account_ID` = $Account_ID then SUM(Total_Bricks) ELSE 0 end as $AccountName,
ASE WHEN Account_ID = $Account_ID then SUM(Kaat_Bricks) ELSE 0 end as $AccountName"

代码错误

使用'和"
<br />不要使用无关标签

建议

使用变量（$Account_ID）代替实际的数组指针（$value['Account_ID'];） - 易于理解且易于调试

在codeigniter中使用字符串变量作为查询

1 个答案: